Chapter 4.1 Quiz

Question 1

Asexual Reproduction (cloning)

Answer 1

-One offspring from one parent
-Offspring are identical to parent cell
-Little to no genetic variation

Question 2

Sexual Reproduction

Answer 2

-Needs fusion of two sex cells (sperm & egg)
-Genetic material is a combination of the two
-Produces genetic variation in the offspring

Question 3

Why asexual reproduction?

Answer 3

1. Growth
2. Repair
3. Replacement

Question 4

The Cell Cycle

Answer 4

-A continuous process of growth & division
-95% interphase, 5% mitosis

Question 5

Interphase

Answer 5

-Is the time between nuclear divisions
-Cells grow by doubling cytoplasmic components including chromosomes
-Repairs to damaged cell parts or programmed cell death
-Chromosomes are uncondensed, collectively referred to as chromatin

Question 6

Mitosis

Answer 6

PMAT
-Asexual
-Daughter cells have the same # of chromosomes as the parent cell. (46 for humans)
-All cells in the human body are derived from the one fertilized egg cell at conception

Question 7

Prophase

Answer 7

-Chromatin condense into chromatids and pair off into sister chromatids held by a centromere
-In animal cells the centrioles move to opposite poles of the cell
-Spindle fibres attach to centrioles
-Most plants don’t have centrioles but spindle fibres still form
-Nuclear membrane fades and dissolves to allow for separation of the chromosomes and cell organelles

Question 8

Metaphase

Answer 8

-Sister chromatids move towards the middle of the cell/equatorial plate
-Spindle fibres align the pairs into position

Question 9

Anaphase

Answer 9

-Centromeres divide
-The sister chromatids pull apart and move to opposite poles of the cell

Question 10

Telophase

Answer 10

-Chromosomes reach opposite poles of the cell, begin to lengthen & relax
-Spindle fibres dissolve
-Nuclear membrane begins to form around each new mass of chromatin

Question 11

Cytokinesis

Answer 11

-Division of the cytoplasm
-Two new daughter cells are now separate
-In animal cells, a cleavage furrow formed
-In plant cells a cell plate is formed between the two cells which becomes a cell plate later
-Cells continue back into interphase

Question 12

Chromosomes

Answer 12

Genetic material/DNA in nucleus which is condensed, folded, and packaged with Histone Proteins. Packaged DNA structures are called Chromosomes.

Question 13

Stages of Interphase

Answer 13

-G1 - cell grows to allow space for duplicate organelles
-S - DNA is synthesized/copied so cell knows how to replicate and perform its duties
-G2 - Cell grows more/again to prepare for mitosis

Question 14

Deox-yribo-nucleic Acid

Answer 14

DNA, a macromolecule, made up of nucleotides. The sequence of groups of nucleotides / genes creates certain traits which are passed down to offspring

Question 15

Structure of a Nucleotide

Answer 15

Each nucleotide is made of 3 parts:
1. A phosphate group
2. A sugar (deoxyribose)
3. A nitrogenous base ( Adenine, Guanine, Cytosine, Thyamine)
A=T, C≡G - 2 or 3 hydrogen bonds

Question 16

Genome

Answer 16

-The complete DNA sequence in every chromosome in every cell of an organism.
-Specific to a species, but individuals within it have slight variations.

Question 17

Gene

Answer 17

-Contain the instructions for the production of proteins which make up the structure of cells & control their function

Question 18

Paired Chromosomes

Answer 18

-# of individual chromosomes each cell has varies from species to species
-Human somatic(body) cells have 46 chromosomes
-Organized into 23 pairs, one from mom, one from dad
-One pair is sex chromosomes - other 22 are called autosomes

Question 19

Homologous Chromosomes

Answer 19

-Pairs of chromosomes that appear similar
-Contain genes for the same traits at the same locations
-May carry different alleles(forms of the gene ex. one says blond hair, the other says brown)

Question 20

Karyotypes

Answer 20

-A cell sample is collected, treated to stop mitosis during metaphase
-sample stained to show banding
-Chromosomes are sorted from longest to shortest, and paired
-Autosomes numbered 1-22
-Sex chromosomes labeled x or y.